Department of Applied Physics, Curtin University of
Technology, Perth, Western Australia

Abstract: The biennial review of atomic-weight, Ar(E),
determinations and other cognate data have resulted in changes for the
standard atomic weights of the following elements:

From

To

Zinc

65.39 ± 0.02

65.409 ± 0.004

Krypton

83.80 ± 0.01

83.798 ± 0.002

Molybdenum

95.94 ± 0.01

95.94 ± 0.02

Dysprosium

162.50 ± 0.03

162.500 ± 0.001

Presented are updated tables of the standard atomic weights and their
uncertainties estimated by combining experimental uncertainties and
terrestrial variabilities. In addition, this report again contains an
updated table of relative atomicmass values and half-lives of selected
radioisotopes. Changes in the evaluated isotope abundance values from
those published in 1997 are relatively minor and will be published in
a major review of each element in 2003. Many elements have a different
isotopic composition in some nonterrestrial materials. Some recent data
on parent nuclides that might affect isotope abundances or atomic-weight
values are included in this report for the information of the interested
scientific community.